This invention generally pertains to aircraft brakes and more particularly to multiple brake configurations as may be found on commercial and/or military transport aircraft More specifically, the invention provides a method of increasing the service life of carbon disks as used in multi-disk brake assemblies of large aircraft.
Refurbishment of brakes for large aircraft requires taking the aircraft out of service for a period of time such that worn disks of a brake disk stack may be replaced. Such down-time of these type aircraft is costly to the industry and it would be extremely beneficial if down-time could be shortened or, alternatively, the period between brake refurbishment lengthened. Manufacturers of aircraft brake assemblies have designed features into the assembly which attempt to make brake disk replacement more efficient, however, these efforts have met the limit and aircraft down-time remains a costly procedure.
While considerable attention has been given to the design of aircraft brake assemblies, brake service life is primarily determined by the number of landing stops which such brake assemblies are subjected to. For example, a particular brake disk stack may be functional for two thousand landings before it must be taken out of service and inspected for wear. At this point in the brake life, the disk components will probably be completely replaced with new disks. While it would seem to the casual observer that the greatest brake wear occurs during high-speed stops upon landing of an aircraft, a large proportion of brake wear actually occurs prior to take-off when the aircraft experiences numerous taxi stops. These taxi-snub cycles are more prevalent because of the increased traffic at congested airports from which these aircraft operate. During these taxi stops, all of the brakes on the aircraft are put into operation regardless of the type of braking being applied, i.e., whether the aircraft is brought to a full stop or just slowed.
In accordance with a primary aspect of the present invention, a method is provided which increases the length of time between major brake overhauls when the disks of the brake disk stack are sufficiently worn and must be replaced.